Advise on Souring a beer post-fermentation

[kirklandj99]

I brewed ~5 gallons of a raspberry wheat beer that turned out pretty tasty. I was thinking about pulling a gallon off and trying to sour it. I didn't necessarily want all 5 gallons of it soured. Can you do this after fermentation? Everything I see seems to add a Lacto starter to the mash/boil, but is it possible to add a little more sugar and some Lacto or ... after the fact and to sour a small batch? Any advice is appreciated. I have a small carboy that I can dedicate to sour beers, so I don't have to worry about "infecting" every other beer down the road by not having the bugs go through the boil.

Thanks

 

[FlyDoctor]

The short answer is yes - but I haven't done it. I've read about people routinely fermenting a wort first with an ale yeast, then pitching something like roselare to sour. There are many products left in the beer that sach yeast cannot eat - but others like bacteria and Brett can use. It is the recommended method of Jamil Z to brew a Falnder red.

 

[Calder]

Lacto, sour mash, kettle mash, are all processes for quickly making simple sours. Berliner Weisse, is the type of beer, simple, clean with a non-complex sourness.

Flanders Reds, Lambics, and the type are more complex, and use a number of bacteria and yeast to get their sourness and complex profile. These will take a year or more. If you want to make one, drink a sour beer with viable bugs (Jolly Pumpkin, or the like), and pitch the dregs in your beer. Place on an airlock and forget about it for a year.

 

[Qhrumphf]

Lacto, sour mash, kettle mash, are all processes for quickly making simple sours. Berliner Weisse, is the type of beer, simple, clean with a non-complex sourness.

Flanders Reds, Lambics, and the type are more complex, and yse a number of bacteria and yeast to get their sourness and compkex profile. These wil take a year or more.

What he said.

Best bet, take 0.5-1 pound of maltodextrin, boil in a couple cups of water (as little as it takes to dissolve it), boil it down and add it. And then add dregs from a few viable sour beers (see The Mad Fermentationist's blog for which beers are viable). That'll get you better results than the commercial sour blends. Maltodextrin will add bug food, without your primary yeast eating it.

Be prepared to leave that gallon in the fermenter for 1-3 years. You may get decent results after 6 months, but I wouldn't plan on it.

Sour mashes/kettle souring/whatever method of pre-boil souring is for simple clean lactic sourness. You won't get the layers and layers of complexity you get with a proper aged sour.

 

[feinbera]

What's the FG on that wheat beer? If you go the dregs route, they'll chew that sucker down to 1.005 - 1.000, so, if the brewer's yeast finished well above that (say, 1.010 or higher), there will be plenty of sugars for the bugs to chew on, even without adding maltodextrin. That's not to say it may not be beneficial, but it may not be absolutely necessary.

Another thing you can do to give the dregs a solid start would be to feed them maybe half a cup of 1.020ish DME wort to get them moving before you add them to the beer. You can do this right in the bottle (although, if you're pitching multiple bottles, you may as well combine into one), stick an airlock on there, you should see some bubbling activity and quite possibly a baby pellicle.

 

[beergolf]

One thing to consider is the IBU's Too high and it will inhibit the lacto.